Description: This interface represents a delegate to be used for external
transaction management. The implementing class may interface to an OMG OTS service,
a Java JTA service or a manufacturer's specific implementation of these services.

Responsibilities:

Define the API for UnitOfWork to add a listener to the externally controlled transaction.

setSession

initializeSequencingListeners

void initializeSequencingListeners()

INTERNAL:
Initializes sequencing listeners.
Always clears sequencing listeners first.
There are two methods calling this method:
1. setSession method - this could lead to initialization of sequencing listeners
only if sequencing already connected (that would happen if setSession is called
after session.login, which is normally not the case).
2. in the very end of connecting sequencing,
after it's determined whether sequencing callbacks (and therefore listeners)
will be required.